A patient-adapted navigator tracking approach for prospective 3D respiratory motion correction in free-breathing myocardial perfusion imaging

H. Pedersen, S. Ringgaard, W. Y. Kim The MR Research Centre, Skejby Hospital, Aarhus University Hospital, Aarhus N, Denmark INTRODUCTION Quantitative analysis of myocardial perfusion using free-breathing first-pass perfusion MRI is degraded by respiratory induced motion of the heart. Conventional strategies to correct this motion include the manual alignment of each image to fit a reference image and automated retrospective registration algorithms, such as [1]. However, with current 2D multi-slice techniques, the through-plane motion cannot be corrected after the acquisition due to the poor spatial resolution in the slice-selection direction (≥10 mm). Therefore, the purpose of this work is to develop a prospective method of both inand through-plane correction applicable to free-breathing myocardial perfusion imaging. The implemented approach is based on real-time navigator tracking [2] with the use of subject-specific scale factors to relate diaphragmatic and cardiac motion. The scale factors were estimated from a free-breathing calibration scan [3] to allow accurate prediction and correction of the cardiac motion during the scan. The efficiency of the strategy was evaluated in healthy volunteers, and a firstpass perfusion study was performed to demonstrate the clinical potential of the technique.